WASMII, a virtual hardware system that executes data
ow algorithms, is based on an MPLD, an extended FPGA with multiple sets of conguration SRAM. Although we have developed an emulation system and software environment for WASMII, it has tended to be unrealistic due to the diculty of the MPLD implementation. However, with recent technologies of semiconductors, an FPGA and DRAM can be implemented into a single LSI chip. We propose novel virtual hardware called HOSMII using such an FPGA/DRAM chip which can hold hundreds of conguration data and switch them instantaneously.